JP2012234015A - Image processing apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of suppressing variation in image quality caused by the types of photoreceptors mounted in an electrophotographic image forming apparatus in which a plurality of types of photoreceptors are used.SOLUTION: A plurality of screens used in performing screen processing on image data are stored in a screen storage region 132 of an image forming apparatus 1. A parameter selection part of the image forming apparatus 1 selects one of the plurality of screens depending on the drum life value with reference to a drum life value stored in a drum life value storage region 131. A screen processing part performs screen processing on the image data to be processed using the selected screen. The image data subjected to screen processing is supplied to an image forming section 17 to form an image on a recording medium according to the supplied image data.

Description

  The present invention relates to an image processing apparatus and an image forming apparatus.

  In an image forming apparatus that performs an image forming process using an electrophotographic method, when the photosensitive drum is used for a predetermined time or more, the photosensitive drum may be deteriorated due to wear or the like, and the image quality may be lowered. Therefore, such an image forming apparatus has a configuration in which a deteriorated photosensitive drum can be replaced with another photosensitive drum (see, for example, Patent Document 1).

JP-A-8-110744

  The present invention provides a technique capable of suppressing variations in image quality caused by the types of mounted photoconductors in an electrophotographic image forming apparatus using a plurality of types of photoconductors. Objective.

  An image processing apparatus according to a first aspect of the present invention includes an information acquisition unit that acquires information about the type of a photoconductor mounted on an image forming unit that forms an image on a recording medium using the photoconductor, According to the information acquired by the information acquisition means from among a plurality of parameters stored in the parameter storage means for storing a plurality of parameters used when generating data for forming an electrostatic latent image on the surface Parameter selection means for selecting any one of them, data conversion means for converting the first image data into second image data using the parameter selected by the parameter selection means, and data converted by the data conversion means Output means for outputting second image data to the image forming means.

  An image processing apparatus according to a second aspect of the present invention is the image processing apparatus, wherein the parameter is a screen used in screen processing, and the parameter selection unit is configured to select the parameter according to the acquired information. One of the plurality of screens stored in the storage means is selected, and the data conversion means performs screen processing on the first image data using the screen selected by the parameter selection means. It is characterized by that.

  In the image processing apparatus according to claim 3 of the present invention, in the image processing apparatus, the information acquisition unit acquires a life value representing a life of the photoconductor, and the parameter selection unit includes the acquired life value. Is compared with a predetermined threshold value, and the parameter is selected according to the comparison result.

  According to a fourth aspect of the present invention, in the image processing apparatus, the parameter selection unit selects a predetermined parameter when the acquisition unit cannot acquire the information. Features.

  The image processing apparatus according to claim 5 of the present invention is the image processing apparatus, wherein the parameter selection unit forms an image on the recording medium when the acquisition unit cannot acquire the information. The apparatus is controlled so as not to exist.

  An image forming apparatus according to a sixth aspect of the present invention includes the image processing apparatus and the image forming unit.

According to the image processing apparatus of the first aspect, for an electrophotographic image forming apparatus in which a plurality of types of photoconductors are used, data conversion is performed using parameters according to information regarding the type of the mounted photoconductor. Compared to the case where it is not performed, it is possible to suppress variations in image quality caused by the type of the mounted photoconductor.
According to the image processing apparatus of the second aspect, it is possible to perform screen processing using a screen suitable for each of a plurality of types of photoconductors.
According to the image processing apparatus of the third aspect, it is not necessary to separately provide information for determining the type of the photoreceptor.
According to the image processing apparatus of the fourth aspect, it is possible to continue the image forming process desired by the user even when an unexpected photoreceptor is mounted on the image forming apparatus main body.
According to the image processing apparatus of the fifth aspect, the image forming process can be stopped when an unexpected photoreceptor is mounted on the main body of the image forming apparatus.
According to the image forming apparatus of the sixth aspect, in the electrophotographic image forming apparatus in which a plurality of types of photoconductors are used, data conversion is performed using parameters according to information regarding the type of the mounted photoconductor. Compared to the case where it is not performed, it is possible to suppress variations in image quality caused by the type of the mounted photoconductor.

2 is a block diagram illustrating an example of a hardware configuration of an image forming apparatus. FIG. 2 is a diagram illustrating an example of a configuration of an image forming unit. FIG. 2 is a block diagram illustrating an example of a functional configuration of an image forming apparatus. FIG. 6 is a flowchart illustrating a flow of processing performed by the image forming apparatus.

<Configuration>
FIG. 1 is a block diagram showing an example of the configuration of an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 is an example of an image forming apparatus according to the present invention. The image forming apparatus 1 is an apparatus that forms an image using an electrophotographic method. An image forming function that forms an image on a recording medium such as paper according to data sent from another computer such as a personal computer. A copying function for scanning, a scanning function for reading an image formed on a recording medium, and the like. The functions provided in the image forming apparatus 1 are not limited to these functions, and may include, for example, a facsimile function. Further, the image forming apparatus 1 is not limited to the one having all the functions described above. For example, the image forming apparatus 1 may have a configuration having an image forming function and a copying function and not having other functions. The recording medium on which an image is formed by the image forming apparatus 1 is not limited to paper, and may be a transparent synthetic resin sheet such as an OHP (OverHead Projector) sheet. It may be of the material.

  As shown in the figure, each part of the image forming apparatus 1 is connected to a bus 11, and exchanges data between each part via the bus 11. In the figure, the control unit 12 includes a CPU (Central Processing Unit) 121, a ROM (Read Only Memory) 122, and a RAM (Random Access Memory) 123, and forms an image according to a computer program stored in the ROM 122 or the storage unit 13. The apparatus 1 is controlled. The storage unit 13 is a storage unit such as a hard disk, and stores various programs such as a program related to the control of the image forming apparatus 1. The operation display unit 14 includes a liquid crystal display that functions as a touch panel, and the user of the image forming apparatus 1 performs various operations by touching the liquid crystal display. The communication unit 18 is connected to the communication line 2 with a communication cable, and performs data communication with other devices connected to the communication line 2. Examples of the communication line 2 include a telephone line and a LAN (Local Area Network).

  The image reading unit 15 includes an optical system member (not shown), optically reads an image of a document, and generates image data representing the read image. The image processing unit 16 performs various types of image processing such as color correction and gradation correction on the image represented by the input image data, and yellow (Y), magenta (M), cyan (from the image processed image). C) Image data of each color image of black (B) is generated, screen processing is performed on the generated image data, and the image data is output to the image forming unit 17. The image processing unit 16 is configured by an integrated circuit such as an ASIC (Application Specific Integrated Circuit).

  The image forming unit 17 forms an image on a recording medium by electrophotography. The image forming unit 17 is an example of an image forming unit that forms an image on a recording medium using a photoconductor. FIG. 2 is a diagram illustrating an example of the configuration of the image forming unit 17. In the figure, photosensitive drums 171Y, 171M, 171C, and 171K are photosensitive drums each having a photoconductive layer such as an organic photosensitive material formed on the surface thereof. The chargers 172Y, 172M, 172C, and 172K respectively apply charges with a charging bias in which AC and DC (direct current) are superimposed on the surface of the photosensitive drums 171Y, 171M, 171C, and 171K, and uniformly charge the chargers. It is. The exposure device 173 is an exposure device including a beam emission source such as a laser diode. The exposure unit 173 exposes the photosensitive drums 171Y, 171M, 171C, and 171K according to the image data supplied from the image processing unit 16, and electrostatic latent images on the surfaces of the photosensitive drums 171Y, 171M, 171C, and 171K. Form.

  The toner cartridges 174Y, 174M, 174C, and 174K store yellow, magenta, cyan, and black toners, respectively, and supply them to the developing units 175Y, 175M, 175C, and 175K as necessary. The developing devices 175Y, 175M, 175C, and 175K form toner images by attaching toner to the electrostatic latent images formed on the surfaces of the photosensitive drums 171Y, 171M, 171C, and 171K, respectively.

  The primary transfer rolls 176Y, 176M, 176C, and 176K face the photosensitive drums 171Y, 171M, 171C, and 171K through the intermediate transfer belt 177, respectively, and transfer the toner images to the intermediate transfer belt 177 at the facing positions. The intermediate transfer belt 177 holds the toner images transferred by the primary transfer rolls 176Y, 176M, 176C, and 176K, respectively. The intermediate transfer belt 177 is supported by a plurality of support rolls 178 and moves while circling in a direction indicated by an arrow A1 in the drawing. The secondary transfer roll 179 transfers the toner image transferred to the intermediate transfer belt 177 to a recording medium. The transport roll 180 transports the recording medium. The fixing device 181 fixes the toner image on the recording medium by heating and pressing the recording medium on which the toner image is transferred by the secondary transfer roll 179.

  A plurality of types of photosensitive drums can be attached to and detached from the image forming apparatus 1, and a user of the image forming apparatus 1 forms an image of a desired type of photosensitive drum according to his / her application. Used by attaching to the device 1. Here, two types of photosensitive drums are used: a “standard type” photosensitive drum and a “long life type” photosensitive drum. The “standard type” photosensitive drum is a commonly used photosensitive drum. On the other hand, the “long life type” photosensitive drum has higher wear resistance and scratch resistance compared to the standard type and can form an image over a long period of time. “Long life type” photoconductor drums have a characteristic that they have a long life, but in image formation, the density reproducibility is different from that of standard photoconductor drums. In some cases, it has a characteristic that the reproducibility of the low density is poor.

  As illustrated, the storage unit 13 includes a drum life value storage area 131 and a screen storage area 132. The drum life value storage area 131 stores a drum life value indicating the life of the photosensitive drum mounted on the image forming apparatus 1. The drum life value indicates that the larger the value is, the longer the life is. Therefore, the long life type photosensitive drum has a drum life value larger than that of the standard photosensitive drum. The drum life value is a value determined in advance for each of the photosensitive drums, and is a value that does not change at all during the period of use (that is, the value does not decrease with the degree of use). ) This drum life value is information recorded on the photosensitive drum, and the photosensitive drum is exposed at a predetermined timing such as when the user of the image forming apparatus 1 replaces the photosensitive drum and closes the front cover. The drum life value is read from the body drum and notified to the control unit 12. When the drum life value is notified, the control unit 12 stores the notified drum life value in the drum life value storage area 131. The drum life value is information referred to in various processes such as a process for determining the replacement time of the photosensitive drum. In the case of a photoconductor drum different from a regular product, the drum life value is not written on the photoconductor drum, or the drum life value is not normally read even if the photoconductor drum is mounted on the apparatus. There may be cases where

  The screen storage area 132 stores a plurality of screens used when the image processing unit 16 performs screen processing. The screen storage area 132 is an example of parameter storage means for storing a plurality of parameters used when generating data for forming an electrostatic latent image on the surface of the photoreceptor. The screen processing is processing for converting image data into information represented by halftone dots, and the screen is a parameter that represents the arrangement pattern of the halftone dots. The image processing unit 16 performs screen processing on the image data to be processed using the screen stored in the screen storage area 132, and converts the multi-value data into binary data.

  In this embodiment, the screen storage area 132 includes two types of screens: a standard screen SC1 for a “standard type” photosensitive drum and a long life screen SC2 for a “long life type” photosensitive drum. It is remembered. These parameters are set to values that take into account the characteristics of the respective photosensitive drums. The standard screen SC1 is a screen used in general screen processing. On the other hand, the long life screen SC2 is set to a value that corrects the deterioration in image quality when the “long life type” photosensitive drum is used. Specifically, the value for the long life screen SC2 is set so that the highlight is darker than the standard screen SC1, the value for reducing overexposure is set, and the low screen is low. In the case of density, a value that increases the density is set. When a “long life type” photosensitive drum is used, screen processing is performed using a long life screen SC2 instead of the standard screen SC1, thereby improving image quality when using a “long life type” photosensitive drum. Reduction is reduced.

  Next, the functional configuration of the image forming apparatus 1 will be described with reference to the drawings. FIG. 3 is a block diagram illustrating an example of a functional configuration of the image forming apparatus 1. In the figure, the parameter selection unit 161 and the screen processing unit 162 are each realized by at least one of the control unit 11 and the image processing unit 16. In addition to the screen processing, the image forming apparatus 1 performs various image processing such as color correction and gradation correction. In the example illustrated in FIG. 3, the screen processing is performed in order to prevent the figure from becoming complicated. The configuration related to the image processing is illustrated, and the configuration related to other image processing is not illustrated.

  In the figure, a parameter selection unit 161 is an example of an information acquisition unit that acquires information on the type of a photoconductor, and is selected from among a plurality of stored parameters according to the type of photoconductor mounted on the apparatus. It is an example of the parameter selection means to select either. Here, the parameter selection unit 161 reads (acquires) the drum life value stored in the drum life value storage area 131, and from among a plurality of screens stored in the screen storage area 132 according to the read value. Choose one. More specifically, the parameter selection unit 161 compares the drum life value stored in the drum life value storage area 131 with a predetermined threshold value, and selects a screen according to the comparison result. The parameter selection unit 161 selects the standard screen SC1 when the drum life value stored in the drum life value storage area 131 is equal to or less than a predetermined threshold value, and otherwise selects the long life screen SC2. Select.

  The screen processing unit 162 performs screen processing on the image data to be processed using the screen selected by the parameter selection unit 161, and supplies the image data subjected to the screen processing to the image forming unit 17 (output) To do). The screen processing unit 162 is an example of a data conversion unit that converts the first image data into second data using the selected parameter, and outputs the converted second data to the image forming unit. It is an example of an output means.

<Operation>
Next, processing performed by the image forming apparatus 1 will be described with reference to a flowchart shown in FIG. The image forming apparatus 1 is instructed to execute the image forming process by operating the operation display unit 14 by a user or receiving image data to be processed from an external apparatus. When the execution of the image forming process is instructed, the parameter selection unit 161 of the image forming apparatus 1 refers to (checks) the drum life value stored in the drum life value storage area 131 (step S1). Here, the parameter selection unit 161 determines whether or not the drum life value has been notified (step S2). When the drum life value is stored in the drum life value storage area 131, it is determined that the drum life value is normally notified. On the other hand, when the drum life value is not stored, it is determined that the drum life value is not notified. To do. When the drum life value is notified (step S2; YES), the parameter selection unit 161 compares the drum life value with a predetermined threshold value (step S3), and whether the drum life value is equal to or less than the threshold value. Is determined (step S4). When the drum life value is equal to or less than the threshold value (step S4; YES), the parameter selection unit 161 selects the standard screen SC1 as the screen used for the screen processing (step S5), while the drum life value is less than the threshold value. If it is larger (step S4; NO), the long life screen SC2 is selected as the screen used in the screen processing (step S6).

  When it is determined in step S2 that the drum life value has not been notified (step S2; NO), the parameter selection unit 161 selects the standard screen SC1 as a screen to be used for the screen processing (step S7). . That is, the parameter selection unit 161 selects a predetermined parameter (here, the standard screen SC1) when information for selecting a screen, that is, a drum life value cannot be acquired. Next, the image processing unit 16 performs various types of image processing on the image data to be processed (step S8). In particular, the image processing unit 16 performs screen processing on the image data using the screen selected in step S7. The image data subjected to the image processing is supplied to the image forming unit 17, and the image forming unit 17 forms an image on a recording medium according to the supplied image data.

  As described above, in this embodiment, when a standard type photosensitive drum is mounted on the image forming apparatus 1, the standard screen SC1 is used for screen processing, while the long life type photosensitive drum is used for image formation. When the apparatus 1 is mounted, screen processing is performed using the long life screen SC2. At this time, as described above, the long life screen SC2 is set to a value that suppresses the deterioration in image quality that may occur when the long life type photosensitive drum is used. By using the screen SC2, variations in image quality that can occur are suppressed.

<Modification>
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, It can implement with another various form. An example is shown below. In addition, you may combine each following aspect suitably.
(1) In the above-described embodiment, two types of “standard type” and “long life type” are used as the photosensitive drum, but the type of the photosensitive drum is not limited to these. Alternatively, another type of photosensitive drum may be used. In the above-described embodiment, the parameter selection unit 161 is configured to use the two types of screens, the standard screen SC1 and the long life screen SC2, according to the drum life value. However, there are two types of screens to be used. It is not limited to, and may be more than this. For example, the parameter selection unit 161 may use three different types of screens depending on the life value of the photosensitive drum.

(2) In the above-described embodiment, the parameter selection unit 161 acquires the drum life value indicating the life of the photoconductor drum as the information regarding the type of the photoconductor, but the information regarding the type of the photoconductor is the drum life value. Not limited to this, other information may be used. For example, an identifier (drum ID) for identifying the photosensitive drum may be read (obtained). In this case, for example, the storage unit 13 of the image forming apparatus 1 is configured to hold a table in which the identifier of the photosensitive drum and the screen type are associated with each other, and the parameter selection unit 161 refers to this table to select the screen. You may make it select. Other examples of the information on the type of the photoconductor may be information indicating the material of the photoconductor drum or information indicating the product number of the photoconductor drum. In short, the information regarding the type of the photoconductor may be any information as long as the type of the photoconductor can be identified based on this information.

(3) In the above-described embodiment, the parameter selection unit 161 selects the standard screen SC1 when the drum life value is not notified (see step S7 in FIG. 4). Instead, the parameter selection unit 161 does not perform image formation on the recording medium when the drum life value is not notified (that is, when the information for selecting the parameter cannot be acquired). The image forming apparatus 1 may be controlled.

(4) In the above-described embodiment, the parameter selection unit 161 selects the screen used for the screen processing according to the type of the photosensitive drum, but the parameter to be selected according to the type of the photosensitive drum is the screen. However, other parameters may be used. For example, the parameter selection unit 161 may select a lookup table that is referred to in the tone adjustment process for adjusting the gradation characteristics of the image according to the type of the photosensitive drum. This lookup table may be, for example, a set of data in which tone values of image data are used as input values and output values, and specific output values are associated with specific input values. Further, as another example of the parameter, for example, the parameter selection unit 161 is referred to when converting the image data expressed by the gradation value of the RGB color space into the image data expressed by the gradation value of the YMCK color space. The conversion parameter to be used may be selected according to the type of the photosensitive drum. As described above, the parameter selected according to the type of the photosensitive drum may be any parameter as long as it is used in the image processing performed by the image processing unit 16. In particular, it may be a parameter used when generating data for forming an electrostatic latent image on the surface of the photosensitive drum.

(5) In the above-described embodiment, the image processing unit 16 that performs image processing on image data is configured by an integrated circuit such as an ASIC independent of the control unit 12, but is not limited thereto, and image processing is not limited thereto. The unit 16 may be configured as software by causing the control unit 12 to read out and execute a computer program stored in the ROM 122 or the storage unit 13.

(6) The programs stored in the ROM 122 or the storage unit 13 described above are a magnetic recording medium (magnetic tape, magnetic disk (HDD (Hard Disk Drive), FD (Flexible Disk), etc.)), optical recording medium (optical disk, etc.). ), And stored in a computer-readable recording medium such as a magneto-optical recording medium or a semiconductor memory. Alternatively, it may be downloaded to the image forming apparatus 1 via a communication line such as the Internet.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Communication line, 11 ... Bus, 12 ... Control part, 13 ... Memory | storage part, 14 ... Operation display part, 15 ... Image reading part, 16 ... Image processing part, 17 ... Image forming part, 18 ... Communication unit, 121 ... CPU, 122 ... ROM, 123 ... RAM, 131 ... Drum life value storage area, 132 ... Screen storage area

Claims (6)

An information acquisition means for acquiring information relating to the type of the photoreceptor mounted on the image forming means for forming an image on a recording medium using the photoreceptor;
Acquired by the information acquisition means from among a plurality of parameters stored in a parameter storage means for storing a plurality of parameters used when generating data for forming an electrostatic latent image on the surface of the photoreceptor. Parameter selection means for selecting one according to information;
Data conversion means for converting the first image data into second image data using the parameter selected by the parameter selection means;
An image processing apparatus comprising: output means for outputting the second image data converted by the data conversion means to the image forming means. The parameter is a screen used in screen processing,
The parameter selection means selects any one of a plurality of screens stored in the parameter storage means according to the acquired information,
The image processing apparatus according to claim 1, wherein the data conversion unit performs a screen process on the first image data using a screen selected by the parameter selection unit. The information acquisition means acquires a life value representing the life of the photoreceptor,
The image processing apparatus according to claim 1, wherein the parameter selection unit compares the acquired life value with a predetermined threshold and selects the parameter according to a comparison result. The image processing apparatus according to claim 1, wherein the parameter selection unit selects a predetermined parameter when the acquisition unit cannot acquire the information. . The apparatus according to any one of claims 1 to 3, wherein the parameter selection unit controls the apparatus not to form an image on the recording medium when the acquisition unit cannot acquire the information. The image processing apparatus according to any one of the above. The image processing apparatus according to any one of claims 1 to 5,
An image forming apparatus comprising: the image forming unit.

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